99mTc-SnF2 colloid "LLK": particle size, morphology and leucocyte labelling behaviour

McClelland, C.M. and Onuegbulem, E. and Carter, Neil and Leahy, Maeve and O'Doherty, Michael J. and Pooley, F.D. and O'Doherty, T. and Newsam, Ray J. and Ensing, G.J. and Blower, Philip J. (2003) 99mTc-SnF2 colloid "LLK": particle size, morphology and leucocyte labelling behaviour. Nuclear Medicine Communications, 24 (2). pp. 191-202. ISSN 0143-3636. (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)

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99mTc-SnF2 colloid (Radpharm LLK) leucocyte labelling agent is used in whole blood, exploiting phagocytosis. The objectives of this work were to optimize leucocyte labelling in leucocyte-enriched plasma, and to investigate: (i) the effect of temperature and other factors on labelling efficiency; (ii) the selectivity for different leucocyte types; (iii) the viability of the labelled cells and efflux of the radiolabel; and (iv) the physical characteristics of the colloid. Density gradient centrifugation was used to investigate the labelling efficiency, cell selectivity and efflux, Trypan blue to study the viability, and laser scattering, electron microscopy and membrane filtration to investigate particle size and morphology. Particles appeared as loose, coiled, chain-like aggregates of much smaller particles (<0.05 microm). The aggregate diameter ranged from <0.1 to >5 microm and increased with time. The distribution of radioactivity amongst the particle sizes varied widely. The labelling efficiency in leucocyte-rich plasma was enhanced at 37 degrees C compared to room temperature, and by centrifuging during labelling. The selectivity for different leucocyte types varied markedly between batches and blood samples, in some cases showing preference for mononuclear cells and in others for granulocytes. Viability was excellent and comparable with 99mTc-hexamethylpropyleneamine oxime (99mTc-HMPAO)-labelled cells. A significant fraction of radiolabel, comparable to that observed with 99mTc-HMPAO, was lost from leucocytes during incubation in vitro over 4 h. Thus, 99mTc-SnF2 is a convenient, efficient labelling agent for leucocytes, but shows variable cell selectivity which may be linked to particle size variability, and there is significant efflux of radioactivity from labelled cells.

Item Type: Article
Additional information: 0143-3636 (Print) Comparative Study Evaluation Studies Journal Article Research Support, Non-U.S. Gov't Validation Studies
Uncontrolled keywords: Cell Survival/drug effects Cells, Cultured Humans Isotope Labeling/*methods Leukocytes/*metabolism/physiology/*radionuclide imaging/ultrastructure Particle Size Quality Control Radiopharmaceuticals/chemistry/diagnostic use/pharmacokinetics Technetium Compounds/chemistry/*diagnostic use/*pharmacokinetics/pharmacology Temperature Tin Fluorides/chemistry/*diagnostic use/*pharmacokinetics/pharmacology
Subjects: Q Science
Divisions: Faculties > Sciences > School of Biosciences
Depositing User: Sue Davies
Date Deposited: 14 Mar 2009 06:52 UTC
Last Modified: 23 Jun 2014 13:28 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/7162 (The current URI for this page, for reference purposes)
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